1. Field of the Invention
This invention relates to real time testing for continuity in transmission paths through a digital concentrator in subscriber loop digital carrier transmission systems.
2. Description of the Prior Art
Testing for continuity in the path through a telephone switching office has been known for a long time. However, these tests usually involve the use of additional equipment, even for testing in time division multiplex switching offices. One such method is disclosed in U.S. Pat. No. 4,064,369 granted to Mr. Frank E. Battocletti on Dec. 20, 1977.
Similarly, in the subscriber loop plant using digital multiplexed transmission systems, it is likewise desirable to test the path through a digital trunk prior to establishing a talking connection.